1. Field of the Invention
The present invention is directed to a system for automatically obscuring undesirable features in an image region which system combines image convolution and erosion to pull features outside the region into the region using a specially designed kernel, a shaped region of interest adapted to reduce artifacts while obscuring undesirable features and local information.
2. Description of the Related Art
Image processing techniques which improve the appearance of images are well known. Methods for the global reduction of image information in an image are also well known. For example, an image can be made less sharp by blurring the entire image with a convolution whose kernel elements are chosen to suit the particular need. Information describing an image can also be produced with the application of algorithms which compute various features within an image. For example, successive applications of erosion and dilation operations can be used to extract information pertaining to the structure of features within an image.
Techniques for the local enhancement of image information are also well known. Such techniques seek to improve the apparent quality of an image in a restricted area or attempt to derive information about an object in an image.
There are also many standard methods for removing image information which rely on operator interaction. Image editing software tools provide air brushing capability, cloning operations and the like to remove image features directly under the operator's artistic control. Such methods are not automated and all require the supervision of the operator.
Automatic operations which endeavor to effectively obscure portions of an image (indicated by an operator) while leaving the rest of the image unaffected are more difficult (and less sophisticated). Such operations must avoid destroying the overall appearance of the image or its image quality. At the same time, the obscured image portion must not be obvious to the eye and, when more closely examined, should appear as a normal part of the image but without the undesirable features.
What is needed is an automatic operation that merges information outside a region with information inside the region to obscure undesirable features while retaining some of the characteristics of the information in the region and being pleasing to the eye.